function main() {
	let scale=255.0/4000 ;
	let ds=pe.Dataset('modis/mod09cmg', 20230901000000);
	let ds1 = ds.forEachPixel( function(v,i) {
		r=v[0];//modis band1 for red
		g=v[3];//modis band4 for green
		b=v[2];//modis band3 for blue
		if( r>0 ) {
			r=r*scale;
			g=g*scale;
			b=b*scale;
		}else{
			r=g=b=0;
		}
		return [r,g,b] ;
	}) ;
	return ds1;
}